This invention relates to an improvement of a hopper for storing free flowing solid material such as coal, coke or other mineral materials and discharging the stocked material from the bottom thereof when desired.
A conventional hopper of the type set forth above has a substantially inverted conical shape so as to discharge the stocked material from a bottom circular center hole thereof. The tapered peripheral wall of the hopper has a predetermined angle relative to a vertical axis thereof, the degree of inclination of which is determined in accordance with the properties of the material to be stocked in the hopper to allow free flow of the stocked material to the bottom of the hopper.
However, in the conventional hopper, in spite of such inclination of the peripheral wall of the hopper, the stocked material often forms a dome-shaped bridge over the bottom center hole of the hopper during the discharge of the stocked material therefrom. Such dome-shaped bridge prevents any further discharge of the stocked material through the bottom center hole of the hopper. Accordingly, it has been required to break the dome-shaped bridge in the hopper by using a special expensive device or by troublesome manual operation.
Furthermore, it is a recent tendency that the size of a hopper of the type set forth above becomes larger and larger due to necessity of storing a great amount of the material with reduced stock cost. When a hopper having a large diameter is constructed, the height of the hopper is increased in a natural way due to the predetermined inclination of the peripheral wall of the hopper, which will result in the increase of a dead space below the hopper. In addition, the enlargement in scale of the hopper will require a stronger supporting structure for the hopper. Thus, the enlargement of the conventional hopper will not provide any scale merit at all.
Accordingly, an object of the present invention is to provide an improved hopper which will eliminate the above disadvantages.
Another object of the present invention is to provide an improved hopper in which solid material stocked in the hopper can be discharged continuously without being blocked by a bridge of the stocked material.
A further object of the present invention is to provide an improved hopper which is relatively low in structure and does not require a strong support for the hopper.
A still further object of the present invention is to provide an improved hopper which can easily control the amount of solid material to be discharged from the hopper.